Long-term Evolution (LTE) is a standard for wireless communication that seeks to provide improved speed and capacity for wireless communications by using new modulation/signal processing techniques. The standard was proposed by the 3rd Generation Partnership Project (3GPP), and is based upon previous network technologies. Since its inception, LTE has seen extensive deployment in a wide variety of contexts involving the communication of data.
Multicast and broadcast communications from cells to user equipments (UEs) were first introduced in 3G systems and consequently further enhanced for 4G LTE systems. Such types of communications are commonly referred to as enhanced Multicast Broadcast Multimedia Systems (eMBMS). The main enhancements are currently related to using synchronized reception from multiple MBMS cells with a MBMS single frequency network area, with all cooperating cells using similar physical layer transmission parameters.
Device-to-device (D2D) communications are currently being standardized by the 3GPP in the contexts of LTE and LTE Advanced (LTE-A). Limited mechanisms required for public safety applications using D2D are standardized as a part of 3GPP LTE release 12 specification process.